Acute renal failure due to tubulo-interstitial nephritis developed in a 15-year-old girl. The disease was accompanied by uveitis and an inflammatory syndrome, consisting of a markedly increased erythrocyte sedimentation rate and high serum gamma globulin levels. The nephropathy as well as the inflammatory syndrome subsided spontaneously. A topical antiphlogistic treatment healed the ocular disease, which has not relapsed so far. The association of acute tubulo-interstitial nephritis and acute uveitis observed in several patients has led to the identification of a specific syndrome with a very particular symptomatology and course, the so-called TINU syndrome, the interest of which resides in the predictability of the complete reversibility of the nephropathy either spontaneously or after steroid treatment, contrasting with the marked tendency towards relapse of the uveitis. The demonstration of circulating immune complexes in the serum during the acute phase of the illness, as in our patient, further points to the involvement of immune processes in the syndrome, but the origin and pathogenesis remain as yet unknown.